Such devices typically comprise a piston for transmitting energy to the fastening element. The required energy must be provided in a very short time, which is why in so-called spring nailers, for example, a spring abruptly transmits the tensioning energy during the driving process to the piston and accelerates the latter toward the fastening element. The spring is cocked for this purpose with a cocking mechanism, which is in turn supplied by a battery.
WO 2011/157775 A2 describes a driving-in device in which such a spring is automatically uncocked as soon as a user has let go of the driving-in device. The energy is drawn down by a motor or fed back to the battery.
If the battery is inadvertently removed from such a fastener driving device while the spring is cocked, however, the automatic uncocking process cannot be controlled due to the interruption of the power supply.